In this activity the interactivity attempts to train the user in the classification of triangles with respect to sides and internal angles. The user should move the vertices of a triangle on a square grid in order to build the triangle which is required for each challenge. The environment integrates geometry and algebra, prompting many interesting questions. The final challenge asks if it is possible to build an equilateral triangle on a square grid.

This material is based upon work supported by the
National Science Foundation under Grant DUE-0226284.
Any opinions, findings, and conclusions or recommendations
expressed in this material are those of the author(s)
and do not necessarily reflect the views of the
National Science Foundation.